1. Field of the Invention
The present invention relates to an apparatus for manufacturing a spun yarn by twisting an untwisted fiber bundle drafted by a drafting device, by applying a whirling stream of air to the fiber bundle, and more particularly, to a spinning apparatus for a bundle of long fibers.
2. Prior Art
An apparatus for producing a real twisted yarn wherein a guide member is provided within a nozzle block for exerting a turning air stream on a fiber bundle moved out of a drafting device with an extreme end thereof directed at an inlet of a rotating or stationary spindle is known by Japanese Patent Provisional Publication No. 161525/1991.
In the apparatus for producing a real twisted yarn constructed as described above, the fiber bundle moved out of the drafting device is attracted into the nozzle block and exposed to a turning stream in the vicinity of the inlet of the spindle and slightly twisted. At this time, all the fibers of the fiber bundle are positioned in the periphery of the guide member and directly exposed to an air flow to receive a force separating from the fiber bundle. However, since the extreme end of the fiber positioned at the inlet of the spindle is subjected to twisting, it is not easily separated. The separated rear end of the fiber is wound about the outer periphery of the spindle and extends outwardly. The fiber is gradually drawn while turning about the fiber bundle as the fiber bundle runs, and most fibers are spirally wound to form a real twist-like spun yarn.
The spinning apparatus described above is an excellent apparatus capable of manufacturing ring-twisted yarns of high quality both in appearance and strength characteristics because of an extremely large quantity of wound fiber. For spinning a long fiber such as wool, a spun yarn bundle, as shown in FIG. 8, which has much core fiber and little wound fiber is produced, due particularly in the case of wool to a long and thick fiber and a small number of component fibers in yarn.
In a general cotton yarn, the mean length of the short fibers is in the range of 23-25 mm and the number of short fibers constituting a cotton yarn having an Ne. of 30 is relatively large (on the order of about 100). On the other hand, in a wool yarn, the mean length of the long fibers is in the range of 60-80 mm, and the number of fibers constituting a wool yarn having an Ne. of 30 is relatively smaller (on the order of about 40).
Accordingly, if the long fiber bundle is spun using a known spinning device for a short fiber bundle, a bundled spun yarn as shown in FIG. 8, in which there are less wound fibers, is produced since separation of fibers can not be accomplished adequately and the number of fibers which are constituting wound fibers of a spun yarn is less.